13 December 2023

C4DtoA 4.6.7 uses Arnold 7.2.5.0 and is a feature release bringing major GPU changes including better scaling on multiple GPUs, global light sampling with volumes, improved distance shader, an overlay imager, faster OIDN denoising, and many other improvements and fixes.

Installation

• Download Arnold for Cinema 4D from your Autodesk Account. See Download Arnold for more information about downloading C4DtoA from your Autodesk Account.

• Follow these installation instructions.

Cinema 4D Compatibility

• R25.010 and above
• S26.013 and above
• 2023.0.0 and above
• 2024.0.0 and above

Note: Known issues in the legacy Arnold Shader Network Editor since Cinema 4D S24:

• Drag & drop nodes to the node editor does not work as expected:
  • Drag & drop an Arnold Material to create a reference. A Cinema 4D Object Operator node is created instead of an Arnold Material reference node.
  • Drag & drop an object to create an object reference. A Cinema 4D Object Operator node is created instead of an Arnold object node.
  • Drag & drop a Vertex Map to create a Vertex Map shader. A Cinema 4D Object Operator node is created instead of an Arnold Vertex Map shader.
• Ctrl + drag a shader in the node editor in S24 creates two copies instead of one. shift + drag and Shift + Alt + drag does not work.

Note: Adding shaders to a Node Material from python crashes Cinema 4D 2024.

Enhancements

• GPU renderer overhaul: A large part of the GPU renderer was rewritten using NVIDIA OptiX 8. This allowed numerous improvements such as much faster startup times, lower GPU memory usage, better scaling on multiple GPUs, and faster renders overall. (ARNOLD-9882)

• Global light sampling in volumes: Global light sampling is now supported in volumes. The render time speedup when using global light sampling in volumes depend on the number of lights, but even scenes with only a few lights are faster to render. (ARNOLD-13095)

Below is an equal time render comparison of a scene containing 351 motion blurred mesh lights inside an atmosphere_volume.

• Improved thick curves intersector: Curves in thick mode are on average 10% faster (in some cases, more than 100% faster) and they look better in closeups. (ARNOLD-2875, ARNOLD-8549 and ARNOLD-14391)

• Distance shader in reflections: The distance shader now properly handles secondary paths such as reflections. (ARNOLD-13883)

• Overlay imager: A new imager that allows you to decorate or tag your renders by printing text over the rendered images. Overlay text can use any of the system fonts (TrueType or PostScript), or custom fonts defined via the OPENIMAGEIO_FONTS environment variable. You can include scene and system information, and render statistics, with pre-defined tokens, such as <frame_time>, <samples>, and <camera>. See the Overlay Imager documentation for the full list of tokens. (ARNOLD-14188)

  Note: Text overlay settings in Render Settings and in IPR snapshots are deprecated and will be removed in a future release. Please use the new overlay imager instead.

• GPU denoising in Intel Open Image Denoise: The Intel denoiser was upgraded from version 1.4.1 to 2.1.0, which brings real-time denoising through NVIDIA and Intel GPU support. (ARNOLD-12547)

• Improved IPR render time and interactivity: As a result of an optimization in the display logic of interactive renders, render times in the IPR are now about 1.2x faster, depending on complexity and sampling settings. The improvement is most significant in simple scenes when rendering multiple AOVs on the GPU. (C4DTOA-3075)

• Procedural and volume animation start loop: You can now control looping of frames before the start of an animated procedural or volume, not just frames after the animation. For instance you can freeze the first frame before the animation. (C4DTOA-3087)

• Toon light-group AOVs: The toon shader now outputs AOVs for direct lighting from lights that have a label in their aov parameter. The toon light-group AOVs are named with the toon aov_prefix parameter. For example, if a light has aov = "keylight" and a toon shader has aov_prefix = "myprefix_", then the toon light-group AOV is named "myprefix_keylight". (ARNOLD-9602)

• Automatically create non-existent paths to tx file: Generating a .tx file (maketx, autotx, AiMakeTx) now works even if the paths to the output .tx file do not exist: Arnold now creates those paths. (ARNOLD-14703)

• Faster overlapping volumes: Arnold renders a few percent faster when there are many overlapping volumes. (ARNOLD-14353)

• Scene unit conversion for light intensity: Scene unit conversion is now supported for light intensity in nested procedurals. If a procedural contains a light and its scene units do not match the procedural units, the light intensity is scaled to match the procedural. Conversion is in place for Arnold ass file procedurals, but we do not yet support USD and arbitrary procedural formats. (ARNOLD-9205)

• Scene unit conversion for volume density and emission: Scene unit conversion is now supported for volume density and emission in nested procedurals. If a procedural contains a volume and its scene units do not match the procedural units, volume density and emission are scaled to match the procedural. Conversion is in place for Arnold ass file procedurals, but we do not yet support USD and arbitrary procedural formats. (ARNOLD-9206)

• Improved profiling: Procedural and volume intersection times are now listed separately, instead of being included with the parent BVH. Profiling has also been added in other areas, in particular multithreaded code where helper threads were not being accounted for. This should result in higher quality statistics. (ARNOLD-14443)

• GPU: Better compatibility with CPU rendering: The following CPU features have been ported over to the GPU.

  • Multiple render sessions with GPU (ARNOLD-14145)

  • When rendering on GPU and using per-face displacement shaders, autobump will now match the displacement shader assigned to each face. Previously, autobump would use the first shader applied. (ARNOLD-12796)

  • Motion blur on the implicit sphere primitive. (ARNOLD-12955)

  • Skydome_light.shader parameter. (ARNOLD-13641)

  • The "polygons" edge type in the wireframe. (ARNOLD-12804)

  • OSL LPE writing via debug closures. (ARNOLD-13907)

  • Image shader "file" wrap mode. (ARNOLD-12578)

  • ID mode in utility shader. (ARNOLD-14159)

  • edgelength mode in utility shader. (ARNOLD-14122)

  • The GPU renderers texture filtering logic has been improved such that there is a closer match to the CPU renderer. (ARNOLD-12578)

  • A number of fixes have been made to the GPU renderer's color management logic such that there is a closer match to the CPU renderer. (ARNOLD-12382)

• Updated Autodesk Network License Manager:: Autodesk Network License Manager (NLM) server version 11.19.4.1 is available and includes support for RHEL/Rocky Linux 9 operating systems. You can find the NLM installer in the license/installer folder, and from the Arnold License Manager. (ARNOLD-14429)

USD Enhancements

• USDZ files supported as file format: You can render usdz files with kick, and load them with the usd procedural. usd#1726.
• Orthographic cameras in Hydra: Orthographic Cameras are now supported in the Hydra render delegate. usd#612.
• Pixel Aspect Ratio in Hydra: The Arnold Render Delegate now supports the pixelAspectRatio parameter in RenderSetting primitives usd#658

API changes

• Multiple render sessions on GPU: The GPU can now render multiple render sessions at the same time. (ARNOLD-14145)
• Font API: A new API AiFontGetFamilies and AiFontGetStyles returns the list of available system fonts (e.g. "Arial", "Times New Roman") and font styles (e.g. "Regular", "Bold", "Italic"). AiFontGetFilename returns the path of the file that defines a given font family and style. (ARNOLD-14395)

Incompatible Changes

• Minimum NVIDIA driver requirements for Arnold GPU: Arnold GPU requires 535.104 or higher drivers on Linux and 537.13 or higher on Windows.
• GPU cache pre-population deprecated: The GPU cache pre-population has been deprecated and calling these functions will now do nothing. (ARNOLD-12135)

Bug Fixes

• C4DTOA-3121 - Scene with custom OCIO config crashes on load

• C4DTOA-3129 - Deprecated shaders are not converted to Node Material

• usd#1709 - Procedural failures if schemas are present

• usd#1713 - Fix coding error "attempt to get string for GfVec4f"

• usd#1732 - Force the color AOV to be interpreted as the Arnold beauty pass

• usd#1735 - Fix usdskel geometry and motion blur interpolation outside the keyframe boundaries

• usd#1524 - Fix material binding on instances under a SkelRoot

• usd#1718 - Support primvars:arnold attributes in Arnold typed schemas

System Requirements

• Windows 10 or later, with the Visual Studio 2019 redistributable.
• Linux with at least glibc 2.17 and libstdc++ 4.8.5 (gcc 4.8.5). This is equivalent to RHEL/CentOS 7.
• macOS 10.13 or later.
• x86_64 CPUs need to support the SSE4.1 instruction set. Apple Mac models with M series chip are natively supported.
• GPU rendering works on Windows and Linux only and requires an NVIDIA GPU of the Ada, Ampere, Turing, Volta, Pascal, or Maxwell architecture. We recommend using the 535.104.05 or higher drivers on Linux and 537.13, or higher on Windows. See Arnold GPU for more information.
• OptiX™ denoiser requires an NVIDIA GPU with CUDA™ Compute Capability 5.0 and above.